10 May 2011

The Devil is in the Assumptions

After seeing several rather embarrassing articles yesterday in the media on the IPCC renewable energy report, it is good to see a few articles that get beyond the initial froth. Here are some excerpts from two very good articles.

As much as $15,000bn – more than the entire US government debt – will have to be found over the next two decades to develop the wind, solar and other renewable energy sources needed to keep global greenhouse gas emissions at bay, a UN report has concluded.

But that is likely to require sustained investment at a time when some of the world’s wealthiest countries may still be struggling with sovereign debt difficulties, a challenge acknowledged by the panel.

“The substantial increase of renewables is technically and politically very challenging,” said Professor Ottmar Edenhofer, co-chair of the IPCC working group that unveiled the report in Abu Dhabi on Monday.

As I suggested yesterday, it remains unclear what the IPCC thinks the costs are associated with its single 77% renewable scenario for 2050, as the costs were reported for only four reference scenarios. Surely they must be higher than the highest reference scenario?

ClimateWire has a much harder-hitting piece, which focuses on the IPCC's reliance on "primitive biomass" in its future scenarios, implying that keeping poor people poor is going to be necessary to achieve high renewable penetration rates:

The world's leading climate change research organization issued a report yesterday that has renewable energy boosters cheering, as it foresees substantial growth in alternative energy sources over the next 40 years.

But the conclusions reached by that report's authors are colored with multiple caveats and uncertainties not captured by initial media coverage. And what the group chooses to identify as "renewable energy" incorporates one controversial practice while leaving others out.

Namely, the coalition of climate scientists includes traditional wood-burning in poor households' cookstoves as an example of renewable energy, though many experts say this is one of the leading causes of deforestation in the world.

ClimateWire explains:

[O]ne complicating factor potentially cancels out much of the optimism espoused yesterday.
The IPCC reaches its estimates by counting among renewable energy sources "traditional biomass" -- the widespread practice in the developing world of scavenging wood for producing charcoal or to burn directly for home heating and cooking.

The U.N.-sponsored body also includes solar photovoltaic, wind power, geothermal and ocean wave technologies as among the renewable sources. But the bulk of the estimated contribution of renewables to global energy supply in its future scenarios is achieved by estimating the energy derived from traditional biomass, according to the "Summary for Policymakers" and charts published by IPCC.

What does this mean? Well, poor people stay poor:

IPCC researchers say their estimates show traditional biomass usage shrinking over time, to be gradually placed by more modern biomass generation, whereby trees felled are actually replanted. But charts showing the possible scenarios of the growth of renewables' share of energy still show biomass as the top source, even out to 2050.

The IPCC's blending of charcoal production with modern practices like biomass cogeneration on farms or wood waste burning near cities makes it difficult to determine how much traditional practices are to be replaced by more modern ones. But the IPCC admits that traditional biomass's share is larger, and the report suggests that its consumption will only fall slightly over the coming decades while modern biomass's share expands gradually.

"The number of people without access to modern energy services is expected to remain unchanged unless relevant domestic policies are implemented," IPCC officials explain.

The IPCC appears to be perfectly willing to make a wide range of assumptions about the implementation of relevant policies to the expansion of renewable energy. Why not make assumptions about polices that seek to make poor people not poor? An interesting choice of what policies to assume are successful and which are not, no?